Additive manufacturing assistance device, additive manufacturing device, additive manufacturing assistance method, and program

Abstract

An additive manufacturing support device includes a building condition acquisition unit configured to acquire information on a shape model of an object and a load condition applied to the object; a stress analysis unit configured to determine a maximum principal stress direction generated in each portion of the object, by stress analysis based on the acquired shape model and load condition; and a trajectory determination unit configured to determine a forming direction of a weld bead on the basis of the maximum principal stress direction and the load condition.

1 . An additive manufacturing support device for, when building a three-dimensionally shaped object by depositing a linear weld bead obtained by melting and solidifying a welding material, supporting determination of a bead forming trajectory representing formation order of the weld bead, the device comprising:
 a building condition acquisition unit configured to acquire information on a shape model of the object and a load condition applied to the object;   a stress analysis unit configured to obtain a maximum principal stress direction generated in each portion of the object, by stress analysis based on the acquired shape model and load condition; and   a trajectory determination unit configured to determine a forming direction of the weld bead on the basis of the maximum principal stress direction and the load condition.   
     
     
         2 . The additive manufacturing support device according to  claim 1 , wherein the trajectory determination unit is configured to determine the bead forming trajectory for each portion of the object such that an intersection angle between the maximum principal stress direction of a corresponding position obtained by the stress analysis and the forming direction of the weld bead becomes small. 
     
     
         3 . An additive manufacturing support device for, when building a three-dimensionally shaped object by depositing a linear weld bead obtained by melting and solidifying a welding material, supporting determination of a bead forming trajectory representing formation order of the weld bead, the device comprising:
 a building condition acquisition unit configured to acquire information on a shape model of the object and a load condition applied to the object;   a temporary trajectory setting unit configured to temporarily set the bead forming trajectory for building the object, on the basis of the acquired shape model;   a stress analysis unit configured to obtain a maximum principal stress direction generated in each portion of the object, by stress analysis based on the shape model and the load condition according to the temporarily set bead forming trajectory; and   a trajectory determination unit configured to obtain a fatigue limit of each portion of the object from the temporarily set bead forming trajectory and the maximum principal stress direction obtained by the stress analysis, and when an obtained predicted fatigue limit of each portion is smaller than a preset design fatigue limit, and to determine the bead forming trajectory of each portion according to the maximum principal stress direction of a corresponding position obtained by the stress analysis.   
     
     
         4 . The additive manufacturing support device according to  claim 3 , wherein the trajectory determination unit is configured to make an intersection angle between the maximum principal stress direction and the forming direction of the weld bead small. 
     
     
         5 . The additive manufacturing support device according to  claim 1 , further comprising:
 a database configured to correlate the fatigue limit of the weld bead with an intersection angle between the forming direction of the weld bead and an acting direction of a stress generated in the weld bead, wherein   the trajectory determination unit is configured to determine, by referring to the database, the forming direction of the weld bead in the bead forming trajectory, within a range of the intersection angle that is equal to or larger than a preset design fatigue limit.   
     
     
         6 . The additive manufacturing support device according to  claim 5 , further comprising:
 a trajectory correction unit configured to, when there is a low-strength portion in which the fatigue limit corresponding to the bead forming trajectory determined by the trajectory determination unit is smaller than a preset design fatigue limit, correct the bead forming trajectory in the low-strength portion such that the fatigue limit increases.   
     
     
         7 . The additive manufacturing support device according to  claim 6 , further comprising:
 a shape change unit configured to, when there is a low-strength portion in which the fatigue limit corresponding to the bead forming trajectory corrected by the trajectory correction unit is smaller than a preset design fatigue limit, change the shape model such that the fatigue limit increases.   
     
     
         8 . The additive manufacturing support device according to  claim 7 , wherein the shape change unit is configured to change a partial structure which the shape model has, into a shape model in which a stress concentration coefficient for the corresponding structure is small, and to output the shape model after change to the building condition acquisition unit. 
     
     
         9 . The additive manufacturing support device according to  claim 1 , wherein:
 the stress analysis unit obtains a stress distribution of the object and extracts a stress concentrating portion having a higher stress concentration coefficient than a surrounding; and   the trajectory determination unit is configured to determine the bead forming trajectory only in the extracted stress concentrating portion according to the maximum principal stress direction.   
     
     
         10 . The additive manufacturing support device according to  claim 5 , wherein:
 the stress analysis unit obtains a stress distribution of the object and extracts a stress concentrating portion having a higher stress concentration coefficient than a surrounding; and   the trajectory determination unit is configured to determine the bead forming trajectory only in the extracted stress concentrating portion according to the maximum principal stress direction.   
     
     
         11 . An additive manufacturing device configured to form the weld bead along the bead forming trajectory determined by the additive manufacturing support device according to  claim 1 . 
     
     
         12 . An additive manufacturing device configured to form the weld bead along the bead forming trajectory determined by the additive manufacturing support device according to  claim 5 . 
     
     
         13 . The additive manufacturing device according to  claim 11 , wherein, while a welding torch whose tip portion is supplied with a filler metal moves along the bead forming trajectory, the supplied filler metal is melted and solidified by an arc to form the weld bead. 
     
     
         14 . The additive manufacturing device according to  claim 12 , wherein, while a welding torch whose tip portion is supplied with a filler metal moves along the bead forming trajectory, the supplied filler metal is melted and solidified by an arc to form the weld bead. 
     
     
         15 . An additive manufacturing support method for, when building a three-dimensionally shaped object by depositing a linear weld bead obtained by melting and solidifying a welding material, supporting determination of a bead forming trajectory representing formation order of the weld bead, the method comprising:
 acquiring information on a shape model of the object and a load condition applied to the object;   obtaining a maximum principal stress direction generated in each portion of the object, by stress analysis based on the acquired shape model and load condition; and   determining a forming direction of the weld bead, on the basis of the maximum principal stress direction and the load condition.   
     
     
         16 . An additive manufacturing support method for, when building a three-dimensionally shaped object by depositing a linear weld bead obtained by melting and solidifying a welding material, supporting determination of a bead forming trajectory representing formation order of the weld bead, the method comprising:
 acquiring information on a shape model of the object and a load condition applied to the object;   temporarily setting the bead forming trajectory for building the object, on the basis of the acquired shape model;   obtaining a maximum principal stress direction generated in each portion of the object, by stress analysis based on the shape model and the load condition according to the temporarily set bead forming trajectory; and   obtaining a fatigue limit of each portion of the object from the temporarily set bead forming trajectory and the maximum principal stress direction obtained by the stress analysis, and when an obtained predicted fatigue limit of each portion is smaller than a preset design fatigue limit, and determining the bead forming trajectory of each portion according to the maximum principal stress direction of a corresponding position obtained by the stress analysis.   
     
     
         17 - 18 . (canceled)